Abstract
"XForms" is the name for W3C's work on the next generation of
Web forms. This work was started in a subgroup of the HTML
Working Group and recently spun off into an independent Working
Group, with a broadened focus. The Working Group is currently
studying how to support forms where the data model is defined by
an XML Schema
plus form specific properties. The previous
version of the XForms Data Model is being obsoleted while
this work is underway.
The plan is for the next revision to this Working Draft to
provide a description of the functional requirements for the
XForms data model and logic, together with proposals for meeting
these requirements using XML Schema plus XForms property
annotations, and an alternative lighter weight syntax aimed at
HTML authors. Later specifications will focus on the user
interface aspects of XForms, and the means to submit, suspend and
resume forms. For more information on the goals of work on
XForms, please look at the XForms
Requirements.
Status of this document
This document is a W3C Working Draft for review by W3C members
and other interested parties. It is a draft document and may be
updated, replaced, or obsoleted by other documents at any time.
It is inappropriate to use W3C Working Drafts as reference
material or to cite them as other than "work in progress". A list
of current public W3C Working Drafts can be found at http://www.w3.org/TR.
Future revisions to this Working Draft will present a proposal
for explicitly representing data models for XForms, the next
generation of Web forms. This document has been produced as part
of the W3C HTML
Activity, following the procedures set out for the W3C Process. The
authors of this document are members of the XForms Working
Group (W3C Members only). This document is for public review,
and comments and discussion are welcomed on the public mailing
list <www-forms@w3.org>. To
subscribe, send an email to <www-forms-request@w3.org>
with the word subscribe in the subject line
(include the word unsubscribe if you want to unsubscribe). The archive
for the list is accessible online.
1. What are XForms?
"XForms" is the W3C's name for work on the next generation of
Web forms. It follows on the extraordinary success of HTML.
Mission
To develop W3C specifications for the next generation of
Web forms The key idea is to separate the user interface and
presentation from the data model and logic, allowing the same
form to be used on a wide variety of devices such as voice
browsers, handhelds, desktops and even paper. XForms bring the
benefits of XML to Web forms, transferring form data as XML.
XForms aim to reduce the need for scripting, and to make it
easier to achieve the desired layout of form fields without
having to resort to using nested tables etc. For further
information, see the Charter.
XForms target two main user communities
-
HTML authors interested in dynamic Web pages and who wish to
achieve more for less effort. A premium is placed on simplicity
and ease of understanding, thus motivating consideration of easy
to learn syntax which fits naturally with scripting.
-
Organizations who have already developed rich data models
using XML Schemas and who now wish to provide Web forms for
entering data conforming to these models. Forms require
additional information beyond that covered by the XML Schema specification. The XForms
Working Group plans to work on identifying ways to supplement
schemas to fill this gap.
What has been achieved so far?
Work on XForms started within a subgroup of the HTML Working
Group. This has recently been spun off into an independent
Working Group, albeit as part of the HTML Activity.
The former subgroup developed two documents:
- XForms
Requirements
- This is the basis of the charter
for the new XForms
Working Group. It sets out requirements under a number of
categories: basic, data modelling, logic, protocols, user
interface, and areas identified for future study.
XForms
Data Model- This sets out a proposal for a data modelling language and
expression syntax for forms. It uses XML Schema for the semantics
of the data types, but re-expresses this in a simple syntax more
likely to win the hearts and minds of typical HTML authors.
This draft has now been obsoleted while the Working Group
studies how to combine XForms with XML Schema.
Work in the subgroup left open the issue of what to do to
support people who prefer to focus on developing business schemas
and who are keen to exploit XML standards such as XML Schema,
XPath, and XML Query etc. While it is easy to transform the
simpler syntax into XML Schema, the reverse is much harder. To
support people who already have developed their business schemas,
we need a way to express the forms specific information in a way
that complements XML Schema.
Where next?
The new XForms
Working Group (W3C members
only) is now working on a re-evaluation of the functional
requirements for XForms The data model is being reworked to allow
people to use XML Schema to define the data model together with
annotations that define form specific properties. This will be
presented in the next revision to this Working Draft. To address
the needs of the HTML authoring community, we plan to retain a
light weight syntax for the data model and logic. Authors will be
able to choose between the light weight syntax and the use of XML
Schema together with the XForms property annotation syntax. The
Working Group expects to publish the revised Working Draft in
October 2000.
2. References
- [XForms
Req]
- "XForms Requirements", M. Dubinko, D. Ragget,
S. Schnitzenbaumer, and M. Wedel, 2000.
Available at: http://www.w3.org/TR/xhtml-forms-req
[XML
1.0]- "Extensible Markup Language (XML) 1.0", T.
Bray, J. Paoli, and C. M. Sperberg-McQueen, 10 Feb 1998.
Available at: http://www.w3.org/TR/REC-xml
[XSchema-1]- "XML Schema Part 1: Structures", H. S.
Thompson, D. Beech, M. Maloney, and N. Mendelsohn, 2000.
Available at: http://www.w3.org/TR/xmlschema-1
[XSchema-2]- "XML Schema Part 2: Datatypes", P. V. Biron,
and A. Malhotra, 2000.
Available at: http://www.w3.org/TR/xmlschema-2